I don't have enough in-depth knowledge to answer these questions. I ope someone else has the time to give you the right answers. Joel Reymont wrote:
On Aug 3, 2005, at 10:40 AM, Fabian wrote:
You should keep in mind that if you use a (V)OID on an 32-bits platform, that you have a limitation of the number of rows that you can contain in a BAT. Also, and OID cannot be bigger than the int it is, so if you do need more rows, or sequence numbers that are higher, you will have to jump over to lng and do the sequence numbers yourself or something.
Is it 2^32-1 for the maximum number of rows in a BAT?
You can never join BATs that are bigger than max(OID), so you have to play tricks like doing the selects on all it's subparts and then unioning the results, given they are small enough to be stored in one BAT.
Are you referring to BAT * BATkunion (BAT *b, BAT *c) in the kernel guide?
I assume that I need to use BATkunion as opposed to BATsunion since I'm looking only at the head column. And that the fragments satisfy the set property since they are fragments of a larger BAT with a non- repeating oid range. Am I thinking right?
Do I need to set any properties on the BAT for the union to work?
Thanks, Joel